- Sexual 'habits'.
- Use of social media.
- Watching the television, listening to the radio, playing computer games, or other ostensibly valid activities that are really 'Valium with a plug'.
- Obsessively checking social and other media sources for the latest unnerving or enervating 'news' story.
- Use of your smartphone (try 'greyscaling' it, i.e. switching the colours off so it's in black, white, and grey).
- Use of sugar.
- Use of caffeine.
This is not about being good or about being pure. This is about mental health.
This is also not about banning 'fun'. There's a difference between genuine fun (playing the piano, going out for dinner with friends, going for a walk) and what is essentially brain-tickling or fucking with your neurochemistry for a quick and worthless buzz. Obsessive news-following has nothing to do with being informed (if you really want to be informed, read proper volumes of non-fiction about current affairs by highly regarded economics and historians, not the latest thing a pal has shared on Facebook); computer games typically have all to do with dopamine and little to do with genuine engagement; etc.
If you're a human being (and that might be a big 'if'), you're wired for addiction, whether or not you're an addict proper, and much of the world of commerce is aimed at exploiting that. If you want better mental health, switch off, and if you can sit through the withdrawal, YOU will switch on.
Be a mensch, not a lizard brain.